Optimizing the value of the posterior condylar offset proximal tibial resection and slope in order to achieve the right balance of the posterior cruciate ligament - clinical application of the molding function of the two parts of the PCL

摘要

Introduction:In order to achieve the right balance of the posterior cruciate ligament using the skeletal method is very difficult, almost impossible (Mahoney). Our hypothesis for the right balance of the PCL by using the skeletal method is based on several defined facts: - PCL is a union based of two anatomically independent, but functionally synergic parts, posteromedial and anterolateral part. - The length of the posteromedial part of the PCL is determined by the belonging of the medial compartment and is shortest in varus and longest in valgus deformation. - The length of the anterolateral part of the PCL, placed centrally is unchangeable (cca 38 mm) in every knee and is independent from the anatomical appearance (deformation). - The cylindrical shape of the distal posterior part of the femur (Ficat) depends of the molding function of the PCL (Kapandji) and is a result of the proportion of the both parts of the PCL that is consisted of: shorter posteromedial part, less bone stock on the medial and more bone stock on the lateral condyle (varus knee) and vice versa, longer posteromedial part, more bone stock on the medial condyle and less on the lateral (valgus knee). According to that, the neutral bone stock is achieved by equalization of the lengths of the two parts (common radius of the cylinder) of the PCL, that is basis for the interligamentary balance of the posterior cruciate ligament.